Illustration of the spectral deblending process at 1.65 μm. Upper left: the initial Z CMa datacube where the two components are resolved. Upper right: during the observation, the adaptive-optics corrected PSF showed a strong astigmatism. To achieve a proper extraction of the spectra of the Z CMa components, we duplicated the HBe star profile to create a PSF model. Lower left: the position and the flux of the individual sources were then retrieved using a modified version of the CLEAN algorithm. Lower right: the extraction error is estimated from the residuals.